Asynchronous Transfer Mode

1. Asynchronous Transfer Mode Instructor Mr. Roy Jolly. By Devender Kasturi

2. Overview • Introduction • Why ATM? • ATM Implementation example. • Business & Profits • ATM Switch • Conclusions • Questions and Suggestions University of North Texas

3. Introduction • ATM – Asynchronous Transfer Mode • Past Situation • Emerged in 1990s but could not take off immediately because of cost of implementation • High cost mainly due to lack of technology to make fast ATM switches • Inability of organizations to use high bandwidth provided by ATM University of North Texas

4. Introduction • Present situation • Emergence of VLSI Technology to make fast transistor switching possible. • Increase in demand for fast networks. • Lowering of prices for ATM switches and Interface cards. University of North Texas

5. What is ATM? • A packet switching network. • Connection oriented network. • Simple concept • Data is broken down into cells • ATM frame consists of 53 such cells • 5 cells are used as header • Remaining 48 cells are the payload University of North Texas

6. Flow Control Virtual Path Identifier Byte 1 Byte 2 Virtual Path Identifier Virtual Path Identifier Byte 3 Virtual Circuit Identifier Virtual Circuit Identifier Payload Type Cell Loss priority Byte 4 Byte 5 Header Error Control (HEC) What is ATM? contd… • ATM Frame • 5 bytes of header University of North Texas

7. ATM AAL’s University of North Texas

8. Physical Layers • Largely ‘physical layer’ independent • E1, E3, DS3, OC3, OC12, etc • Megabits rather than kilobits University of North Texas

9. Why ATM? • Incorporates variety of information • Voice, video, data, multimedia • Applications in the field of: • Business • Manufacturing • Health Care • Government • Software • Legal University of North Texas

10. Why ATM? • Lowers network costs because of a common network. • Higher Bandwidth • Flexible Bandwidth • QOS • Standardization of equipment University of North Texas

11. Implementation Example • Sprint ATM Network • Consists of ATM network with a range of ATM switches and an Integrated Services HUB. University of North Texas

12. University of North Texas

13. ISH ISH ISH ATM Network ISH ISH ISH ISH ISH Sprint ATM Network Structure University of North Texas

14. Integrated Services Hub • Aggregates networks and provide multi service access concentration. • Examples • Cisco 1720 • Cisco 2600 - NxT1 • Cisco 3600 - NxT1 • Cisco 3810 • Nortel Passport 6420 • Nortel Passport 6440 • Nortel Passport 6480 University of North Texas

15. Integrated Services Hub (ISH) Managed Network Service Dedicated IP PBX systems Video LAN Fax Voice Workstation University of North Texas

16. Another Example… ATM Backbone Network of British Airways University of North Texas

17. ATM Growth • Results for backbone technologies adopted obtained from studies by Infonetics Research. • IP and ATM are prevalent networks • MPLS Growing Fast • Suggests Multi-service networks. University of North Texas

18. ATM QOS • Results obtained from Infonetics Research. • ATM dominant. • MPLS growing fast. University of North Texas

19. Sprint Business • Sprint ATM service has been voted #1 in QOS. • Many organizations small or large are adopting this service. • Because of this a lot of profits are being reaped by Sprint. University of North Texas

20. Cisco BPX 8600 Series Switches • Standards-based ATM switch with advanced IP and ATM capabilities. • Designed to meet the demanding, high-traffic needs • Delivers high-performance ATM switching, multi-service adaptation and aggregation University of North Texas

21. Cisco BPX 8600 Series Switches • Up to 20 Gbps of high-throughput switching • Supports a wide range of interfaces, from Frame Relay to full broadband subscriber interfaces • Also supports multi-protocol label switching (MPLS) University of North Texas

22. Cisco BPX 8600 Series Switches • Multi-shelf architecture • Allows users to incrementally expand the capacity of the system as needed and fully utilize the switch fabric • Advanced switching capabilities • Intelligent call processing for Frame Relay and ATM switched virtual circuits (SVCs) University of North Texas

23. Cisco BPX 8600 Series Switches • Reliability • Automatic Routing Management reroutes virtual circuits if a trunk fails • Scalability • High service availability and performance • Robust, redundant architecture University of North Texas

24. Conclusions • ATM network supports constant bit rate and variable bit rate applications. • Organizations are able to run different applications using a common network. • Lower cost of implementation because of a single network. University of North Texas

25. Conclusions • ATM provides good QOS. • Organizations using ATM networks are earning profits. • ATM is a network for the future. • Compatible for implementing MPLS. University of North Texas

26. References • http://www.sprintbiz.com/bizpark/products_services/network • http://www.cisco.com/univercd/cc/td/doc/pcat/bp8600.htm#ov • http://telephonyonline.com/ar/telecom_tough_crowd_sprint/ • http://news.earthweb.com/xSP/print.php/574431 University of North Texas